This project used mixed methods to expand the understanding of social ecological constructs important to youth and develop measures to assess these constructs. Eight focus groups and 24 cognitive interviews were conducted with adolescents and caregivers. These were followed by a survey completed by 440 youth ages 10-21 (average age: 16.38, standard deviation[SD] = 3.04). Qualitative data revealed social ecological constructs that have received little prior research attention. These include three psychosocial strengths: relational motivation (inspiration from key adults), group connectedness (bonded to others in teams or organizations), and mattering (knowing your importance to significant others). One outcome was also identified: family well-being (subjective psychological functioning of the family). Psychometric analyses indicated that the new quantitative measures have good to excellent reliability and validity. The social ecology is complex and extends beyond commonly studied constructs such as social support and collective efficacy. More comprehensive assessments can further research.